i18n: Fix translation of --help [PR93759]

i18n: Fix translation of --help [PR93759]

The first two hunks make sure we actually translate what has been marked
for translation, i.e. the cl_options[...].help strings, rather than those
strings ammended in various ways, like:
_("%s  Same as %s."), help, ...
or
"%s  %s", help, _(use_diagnosed_msg)

The exgettext changes attempt to make sure that the cl_options[...].help
strings are marked as no-c-format, because otherwise if they happen
to contain a % character, such as the 90% substring, they will be marked
as c-format, which they aren't.

2020-02-21  Jakub Jelinek  <jakub@redhat.com>

	PR translation/93759
	* opts.c (print_filtered_help): Translate help before appending
	messages to it rather than after that.

	* exgettext: For *.opt help texts, use __opt_help_text("...")
	rather than _("...") in the $emsg file and pass options that
	say that this implies no-c-format.